Punching apparatus having means to center workpiece



July 27, 1965 c. K. HULEN 3,196,725

PUNCHING APPARATUS HAVING MEANS T0 CENTER WORKPIECE Filed Jan. 28, 1963v 2 Sheets-Sheet 1 'INVENTOR. 614005 Z l/uusu A TTORIVEYS I PUNCHINGAPPARATUS HAVING MEANS T0 CENTER WORKPIECE Filed Jan. 28, 1963 C. K.HULEN July 27, 1965 2 Sheets-Sheet 2 CLAUDE Z ATTORNEYS United StatesPatent 3,196 725 PUNCHING APPARATUS HAVING MEANS T0 CENTER WORKPIECEClaude K. Hulen, 1524 Charlotte, Kansas City, Mo. Filed Jan. 23, 1963,Ser. No. 254,264 Claims. (Cl. 83-389) This invention relates to sheetpunch apparatus, and more particularly to precision devices of thischaracter suitable for use in the graphic arts, such as lithography andengraving.

The principal objects of the present invention are: to provide sheetpunch apparatus having extremely high accuracy and repeatability; toprovide such apparatus Wherein the sheet to be punched is automaticallyclamped in position immediately prior to punching in conjunction withpunch motion; to provide such apparatus which includes anextremelysimple but effective centering device which cooperates with a gauge orwall surface to accurately and quickly center and align a sheet forpunching; to provide a precision machine of this type which prodncesclean, accurately spaced punch openings in a great variety of materialsdifficult to punch and which is easily maintained in sharp condition; toprovide such apparatus which includes a translucent supporting table foreflicient viewing of sheet material being punched; and to provide such aunit which is simple and rugged in construction, portable, and easilyused by relatively inexperienced personnel.

Other objects and advantages of this invention will become apparent fromthe following description taken in connection with the accompanyingdrawings wherein are set forth by way of illustration and examplecertain embodiments of this invention.

FIG. 1 is a fragmentary plan view of punch apparatus embodying thisinvention.

FIG. 2 isa fragmentary perspective view on an enlarged scale of aportion of the punch apparatus, particularly showing the relationshipbetween the punching and holdaiown mechanisms.

FIG. 3 is a fragmentary vertical cross-sectional view on an enlargedscale, particularly showing the hold-down mechanism in clampingposition.

FIG. 4 is a fragmentary vertical cross-sectional view 0 an enlargedscale, particularly showing a punch and a hardened bushing which acts asa die.

FIG. 5 is a fragmentary perspective view on an enlarged scale,particularly illustrating a pulley forming a part of a sheet centeringdevice.

FIG.- 6 is a fragmentary perspective view on a reduced scaleillustrating a precision graphic step and repeat vacuum frame line-uptable having an adjustable precision straight edge with spaced pegs forreceiving a punched masking sheet. I

FIG. 7 is a fragmentary vertical sectional view on an enlarged scaleillustrating the peening or belling of a punch piror to insertion into adie for maintaining sharpness.

Referring to the drawings in more detail:

The reference numeral 1 generally indicates a sheet punch apparatusembodying this invention. The apparatus 1 includes a horizontallyextending sheet or work-supporting table 2 having a translucent cover 3whereby the work may be illuminated from beneath for ease of viewing. Ariser bar 4 is fixed to the table 2 and is positively positioned bymeans of suitable aligning pins 5. Bearing members 6 are spaced alongthe riser bar 4 and extend upwardly therefrom.

A shaft 7 extends parallel to the table 2 and is rotatably mounted inthe bearing members 6. A suitable handle 7 has legs 8 secured to theshaft 7 with set screws 8' and extending laterally therefrom forselectively rotating the 3,195,?25 Patented July 27, 1965 "ice shaft 7through an .arc for reasons apparent hereinafter. Coil springs 9 areengaged respectively with hearing membars 6 and collars 9' fixed to theshaft 7 for resiliently urging the shaft to a rotational position wherethe handle 7' is normally substantially elevated above the table 2.

A plurality of laterally extending punch heads 10 are rotatably fixed tothe shaft 7 by means of set screws 11 extending into a longitudinallyextending groove 12 in the shaft. The punch heads 10 are spaced alongthe shaft 7 and a plurality of vertically extending sleeve bearingreceiving bores '13 are in the riser bar 4 aligned with the punch heads10. Sleeve bearings 14 are supported in the bores 13 and alongitudinally slidable punch 15 is reciprocal in each of the sleevebearings 14. Links 16 are pivotally connected at opposite ends thereofto the heads 10 and the upper ends 17 of the punches 15.

A cut-away portion 18 in the riser bar 4 forms a vertically extendingrear wall surface 19 and facing, horizontally extending, spaced apartupper and lower Wall surfaces 20 and 21 defining a recessed forwardlyopen elongated horizontally extending slot 22 between the riser bar 4and the table 2 for receiving sheets or work to be punched, as discussedhereinafter. The sleeve bearings 14 open at the lower ends thereof atthe upper wall surface 2!) whereby the punches 15 may slide therefrominto the slot 22;

A plurality of receiving bores 23 extend vertically into the table 2 andare respectively aligned with the riser bar bores 13. Hardened bushingsor dies 24 are received and supported in the table bores 23 and each hasa die opening 25 therein opening at the lower wall stuface 21. Thepunches 15 are guided by the sleeve bearings 14 through the slot 22 intothe die opening 25.

A plurality of laterally extending hold-down heads 26 are rotatablyfixed to the shaft 7 by means of set screws 27 engaging the groove 12and are spaced therealong intermediate respective punch heads 10. Aplurality of vertically extending rod receiving bores 28 are located inthe riser bar 4 and aligned with the hold-down heads 26. Verticallyextending rods 29 are slidably received in the rod bores 28 and links 30are pivotally connected to the rods at the upper ends 31 thereof.

An elongated upwardly extending recess 32 is located in each of thehold-down heads 26. A horizontally and norm-ally vertically extendingslot 33 extends through each of the hold-down heads 26 and intersectsthe respective recesses 32. Pins 34 are received in the hold-down headslots 33 and are movable therein vertically (longitudinally) withrespect to the recesses 32. A helical compression spring 35 is retainedin each of the recesses 32 and resiliently bears against the pins 34 forurging same downwardly, the pins 34 pivotally connecting the links 30 tothe hold-down heads 26.

The rods 29 at the lower ends 36 there-of are reduced in diameterforming shoulders 37. The ends 36 extend into the forwardly open slot22. A hold-down bar 38 is located in the slot 22 and has a verticalheight less than the spacing between the upper and lower wall surfacesforming the slot 22. Spaced vertical bores 38' extend through the bar 38and receive the lower ends 36, securing the rods 29 to the bar 38 bymeans of set screws 39 for vertical reciprocation of the bar 38 in theslot 22. The shoulders 37 bear against the hold-down bar 38 to preventdownwardly relative motion of the rods 29 with respect to the bar 38.Bores or openings 40 of slightly greater diameter than the punches 15extend vertically through the hold-down bar 38 for slidably receivingthe lower ends of the punches 15 therethrough.

The punch heads 10 and hold-down heads 26 are rotatably fixed withrespect to each other whereby the bar 38 resiliently engages against thesheet to be punched reams 3 or lower wall surface 21 before the punchesengage in the die openings 25 upon moving the handle 7' through an arctoward the supporting table. Resiliency in the downward engagement ofthe hold-down bar 38 is furnished by the compression of the springs inresponse to movement of the pins 34 in the slots 33.

The dies or hardened bushings 24- open downwardly of the supportingtable 2 and a removable catch tray 41 engaged in table grooves 42 islocated directly beneath the hardened bushings for receiving die cutstherefrom.

A pair of parallel closely laterally spaced upwardly open slots 43 and44 extend transversely across the supporting table 2 adjacent the riserbar 4 and in parallel relation with the rear wall surface 19. Pulleys45, and 46 are located at opposite ends of the slots 43 and 44 and aremounted on the table 2 for rotation about respective vertical axes. Atape or ribbon 47 is engaged with the pulleys and 46 in a loop formingparallel legs 42; and 49 respectively located'in the upwardly open slots43 and 44. A resilient helical tension spring St) is engaged withopposite ends of the tape or ribbon 47 drawing the tape or ribbontightly against the pulleys 45 and 46.

Locating lugs 51 and 52 are longitudinally slidable respectively in theupwardly open slots 43 and 44 and are respectively engaged with the legs48 and 49 of the tape or ribbon 47 by means of set screws 53 extendinginto lug slots 54 receiving the tape or ribbon. The lugs 51 and 52 areadjusted whereby they arrive at the exact center between the pulleys 45and 46 at the same instant when moved toward each other, the tape orribbon 47 insuring that the lugs move simultaneously over equaldistances. Cover plates 55 and 56 are respectively located overone-halfof the upwardly open slots 43 and 44 and are flush with thesurface of the table 2. The plates 55 and 56 prevent unnecessaryinterruption in the continuity of the table surface, but yet permit freesliding of the lugs 51 and 52 respectively over half the Width of thetable 2.

In operation, a work piece such as a masking sheet 57 has the edge 53 tobe punched urged into the slot 22 and against the rear wall surface 19.The lugs 51 and 52 are then urged toward each other and a portion 59 ofthe lugs which extends above the surface of the table 2 contacts lateraledges 60 and 61 of the sheet 57 centering the sheet on the table 2. Withthe lugs 51 and 52. and the rear wall surface 19 simultaneouslycontacting the masking sheet, the sheet is exactly and repeatablylocated with respect to the punches 15 and hardened bushings 24. Bymoving the handle 7' downwardly, the hold-down bar 38 contacts the uppersurface of the masking sheet 57 and clamps same against the table 2 inthe slot 22. Further downward motion of the handle 7' urges the punches15 through the masking sheet, placing spaced punched holes 62 thereincorresponding to the spacing of the punches 15. The punched out portions(not shown) fall into the catch tray 41 for convenient storage untilremoved for disposal. The masking sheet 57, in the illustrated example,may then be engaged with slightly upstanding pegs 63 suitably secured toa precision adjustable straight edge 64 of a stop and repeat line-uptable 65 of the type often used in the graphic arts industry.

Due to the extreme precision possible with the abovedescribed apparatus,the masking sheet 57 or other Work (including, for example, zinc oraluminum metal printing plates) may be'exactly located in desiredposition on the line-up table 65. Subsequent sheets, when punched in theabove-noted manner, will always bear an exact known relationship withthe masking sheet 57 since the holes punched therein will be locatedwith respect to the transverse center line between the lateral edgescontacted by the lugs 51 and 52.

In order to maintain high precision, it is necessary that the punches 15retain a sharp edge where contacting the hardened bushings 24. Aconvenient method for periodically insuring maximum sharpness comprisesremoving the catch tray 41 which exposes the bottom of the hardenedbushing 24, and inserting upwardly therethrough a punch-like member 66(FIG. 7) and driving same (peening) with a hammer or the like (notshown) against the bottom surface 67 of the punches 15. This causes therelatively soft metal. (compared to the bushings or dies 24) formingsame to bell or enlarge to a slightly greater diameter. The punches arethen pushed down against the hardened bushings so that a thin Wire edge(not shown) on the bottom of the punch will be removed and the resultwill be an accurate, positive fit of the lower end of the punch in thedie bore.

In a typical punch apparatus embodying this invention, the punches arespaced apart approximately 4 inches, the spacing being held to atolerance of less than .001 inch. Clean, accurate holes may be punchedin a great variety of difiicult-to-cut sheet materials such'as tissues,vinyls, acetates and, as noted above, zinc or aluminum printing plates.

It is to be understood that while one form of this invention has beenillustrated and described, it is not to be limited to the specific formor arrangement of parts herein described and shown except insofar assuch limitations are included in the claims.

What I claim and desire to secure by Letters Patent is:

1. A sheet punching apparatus comprising:

(a) a sheet supporting table, a riser bar fixed With respect to saidtable and having spaced bearing members extending therefrom, a shaftrotatably mounted in said bearing members, means operably secured tosaid shaft for selectively rotating said shaft through an arc,

(b) punch guide means on said riser bar, a plurality of spaced punchingmembers axially slidable in said punch guide means, one of said punchingmembers being at a center position of a line parallel to said shaft,connecting means between each of said punching members and said shaftfor sliding said punching members in response to the rotation of saidshaft, means forming a recessed open slot adjacent said riser bar forreceiving said punching members thereinto,

(c) means in said table forming a receiving bore with a die opening intosaid slot for each of said punching members and aligned with saidrespective punching members across said slot, said punching membersbeing reciprocably guided through said slot into said receiving boresupon actuation of said shaft rotating means,

(d) rod guide means on said riser bar, a rod slidable in said rod guidemeans, i

(e) a head fixed to said shaft, a slot extending through said head andintersecting said recess,

(f) a pin in said head slot and movabletherein toward and away from saidrecess, a resilient member in said recess and resiliently bearingagainst said pin for urging same tranvsersely of said head slot,

(g) a link pivotally connected between said pin and said rod wherebysaid head, pin and link operatively connect said shaft and said rod forsliding said rod in response to the rotation of said shaft,

(h) a hold-down bar having a height less than the height of said slot,said hold-down bar being operably secured to said rod for reciprocationin said slot,

(i) resilient means between said hold-down bar and said shaft, wherebysaid hold-down bar resiliently engages a sheet in said slot before saidpunching members enter said receiving bore upon actuation of said shaftrotating means,

(j) and adjustable lug means equally and simultaneously movable towardand away from said center position and engageable with a sheet to bepunched to center said one punching member relative to opposed edges ofsaid sheet.

2. A sheet punching apparatus as set forth in claim 1 wherein theconnecting means between each punching member and the shaft includes ahead member on the shaft, a link having one end pivotally connected tothe respective head member and the other end pivotally connected to therespective punching member, and means securing the head member to theshaft for sliding said punching member in response to rotation of saidshaft.

3. A sheet punching apparatus as set forth in claim 2 wherein the punchreceiving bores open through the supporting table with a hardenedbushing in each of said punch receiving bores and having the dieopenings therein and a removable catch tray is engaged in the table forreceiving die cuts from the sheets.

4. A sheet centering device for punching apparatus and the like having asheet supporting table comprising:

(a) means forming a pair of parallel closely laterally spaced upwardlyopen slots extending transversely across said supporting table,

(b) a pulley located at opposite ends of said slots and mounted withrespect to said table for rotation about axes perpendicular to saidtable,

(c) a tape engaged with said pulleys in a loop forming parallel legsrespectively located in said slots, means for drawing said tape tautagainst said pulleys, and

(d) a locating lug slidable in each of said slots and engaged with saidrespective legs, a portion of said lugs extending above the surface ofsaid table for simultaneously contacting opposite edges of a sheet,whereby the sheet is located on said table.

5. In combination with a sheet punching aparatus having a sheetsupporting table and a sheet receiving punching slot with a rearlocating wall surface:

(a) a pair of parallel closely laterally spaced upwardly open slotsextending transversely across said supporting table in parallel relationwith said rear wall surface,

(b) pulleys rotatably mounted at opposite ends of said upwardly openslots, a tape engaged with said pulleys in a loop forming parallel legsrespectively located in said upwardly open slots, resilient means fordrawing said tape taut against said pulleys, and

(c) a locating lug slidable in each of said upwardly open slots andengaged with said respective legs, a portion of said lugs extendingabove the surface of said table for simultaneously contacting oppositeedges of sheets to be punched,

(d) whereby sheets to be punched are centered laterally and squared withrespect to said punch apparatus prior to punching due to simultaneousengagement with said lugs and said rear wall surface.

References Cited by the Examiner UNITED STATES PATENTS FOREIGN PATENTSGermany.

WILLIAM W. DYER, 111., Primary Examiner.

ANDREW R. IUHASZ, Examiner.

1. A SHEET PUNCHING APPARATUS COMPRISING: (A) A SHEET SUPPORTING TABLE,A RISER BAR FIXED WITH RESPECT TO SAID TABLE AND HAVING SPACED BEARINGMEMBERS EXTENDING THEREFROM, A SHAFT ROTATABLY MOUNTED IN SAID BEARINGMEMBERS, MEANS OPERABLY SECURED TO SAID SHAFT FOR SELECTIVELY ROTATINGSAID SHAFT THROUGH AN ARC, (B) PUNCH GUIDE MEANS ON SAID RISER BAR, APLURALITY OF SPACED PUNCHING MEMBERS AXIALLY SLIDABLE IN SAID PUNCHGUIDE MEANS, ONE OF SAID PUNCHING MEMBERS BEING AT A CENTER POSITION OFA LINE PARALLEL TO SAID SHAFT, CONNECTING MEANS BETWEEN EACH OF SAIDPUNCHING MEMBERS AND SAID SHAFT FOR SLIDING SAID PUNCHING MEMBERS INRESPONSE TO THE ROTATION OF SAID SHAFT, MEANS FORMING A RECESSED OPENSLOT ADJACENT SAID RISER BAR FOR RECEIVING SAID PUNCHING MEMBERSTHEREINTO, (C) MEANS IN SAID TABLE FORMING A RECEIVING BORE WITH A DIEOPENING INTO SAID SLOT FOR EACH OF SAID PUNCHING MEMBERS AND ALIGNEDWITH SAID RESPECTIVE PUNCHING MEMBERS ACROSS SAID SLOT, SAID PUNCHINGMEMBERS BEING RECIPROCABLY GUIDED THROUGH SAID SLOT INTO SAID RECEIVINGBORES UPON ACTUATION OF SAID SHAFT ROTATING MEANS, (D) ROD GUIDE MEANSON SAID RISER BAR, A ROD SLIDABLE IN SAID ROD GUIDE MEANS, (E) A HEADFIXED TO SAID SHAFT, A SLOT EXTENDING THROUGH SAID HEAT AND INTERSECTINGSAID RECESS, (F) A PIN IN SAID HEAD SLOT AND MOVABLE THEREIN TOWARD ANDAWAY FROM SAID RECESS, A RESILIENT MEMBER IN SAID RECESS AND RESILIENTLYBEARING AGAINST PIN FOR URGING SAME TRANSVERSELY OF SAID HEAD SLOT, (G)A LINK PIVOTALLY CONNECTED BETWEEN SAID PIN AND SAID ROD WHEREBY SAIDHEAD, PIN AND LINK OPERATIVELY CONNECT SAID SHAFT AND SAID ROD FORSLIDING SAID ROD IN RESPONSE TO THE ROTATION OF SAID SHAFT, (H) AHOLD-DOWN BAR HAVING A HEIGHT LESS THAN THE HEIGHT OF SAID SLOT, SAIDHOLD-DOWN BAR BEING OPERABLY SECURED TO SAID ROD FOR RECIPROCATION INSAID, SLOT, (I) RESILIENT MEANS BETWEEN SAID HOLD-DOWN BAR AND SAIDSHAFT, WHEREBY SAID HOLD-DOWN BAR RESILIENTLY ENGAGES A SHEET IN SAIDSLOT BEFORE SAID PUNCHING MEMBERS ENTER SAID RECEIVING BORE UPONACTUATION OF SAID SHAFT ROTATING MEANS, (J) AND ADJUSTABLE LUG MEANSEQUALLY AND SIMULTANEOUSLY MOVABLE TOWARD AND AWAY FROM SAID CENTERPOSITION AND ENGAGEABLE WITH A SHEET TO BE PUNCHED TO CENTER SAID ONEPUNCHING MEMBER RELATIVE TO OPPOSED EDGES OF SAID SHEET.